# Insulation thickness calculation

1. Sep 27, 2006

hi friends,
I'm an engineer, & recently I face a problem to calculate the thickness of the insulating material in the inlet gas duct of Waste heat recovery type boiler.
Actually, we are executing a project, that the waste coke oven gas is used for generating steam.
for this we introduce a gas duct by which the gas entered into the boiler the temperature of the gas is 1100 degree centigrade. so the duct should be properly insulated. Now how can I select the insulation thickness? & how many layers of insulating materials should be provided? & what type of materials are to be selected?

Mrinal

2. Feb 23, 2007

### eaboujaoudeh

i didn't quite understand u where insulating what from what, but ur dealing with high temperatures here, and i think u should research professional companies, as for the calculations, after u choose the material u want u would be able to get the thermal conductivity constant from it and u can fix the temperature of the other side of the insulation (the temp u want) then u would be able to calculate the thickness of the material.

3. Feb 23, 2007

### FredGarvin

Mrinal,
I would recommend looking at a simple conductive heat transfer first to get a rough idea of what you are looking at. To really know anything you need to define what exactly you mean by "properly insulated." As an engineer you know that statements like that are not usefull at all. You need to establish what your design criteria actually is. Once you do the basics then you can go about refining your calculations by adding things like convection and radiation.

In regards to high temperature insulation, there are plenty of wraps and materials that can handle that temperature. You could look into spray on insulation as well. A 2 second search on google found this as the first hit:

http://www.sandsinsulation.com/